Factors influencing the deformation mechanisms in the intermetallic compounds Al₃Ti and Al₃V

Abstract

The factors influencing the deformation mechanisms in the intermetallic compounds Al₃Ti and Al₃V have been studied. As previously reported, plastic deformation of the former compound involves micro-twinning and glide of partial dislocations with Burgers vectors b given by ½〈110〉 on {001) producing ribbons of antiphase domain boundaries (APBs). In contrast, for Al₃V these mechanisms are not activated and it has been determined that deformation is effected mainly by glide of dislocations with b = 〈110] on . It is proposed that this difference in behaviour is due to the relative stability of the DO₂₂ crystal structure against the Cu₃Ti-type structure (micro-twinning) and DO₂₃ (APBs on the basal planes). It is suggested that increased ductility in these types of compounds may be realized by alloying with elements which reduce the energy difference between the DO₂₂ and Cu₃Ti-type crystal structures for these compounds.